Newsgroups: comp.robotics
Path: cantaloupe.srv.cs.cmu.edu!das-news2.harvard.edu!news2.near.net!howland.reston.ans.net!swrinde!cs.utexas.edu!news.sprintlink.net!pcnet.com!circellar!stephen.griswold
From: stephen.griswold@circellar.com
Subject: WHAT TO SALVAGE? DISK
Message-ID: <9506130106.01K2Q02@circellar.com>
Organization: Circuit Cellar, Inc.
X-Mailer: TBBS/PIMP v3.34
Distribution: world
Date: Tue, 13 Jun 95 01:06:30 -0400
Lines: 53


In comp.robotics newsgroup,
brynn@sashimi.wwa.com (Brynn D. Rogers) wrote about
Re: What to salvage? Disks etc..

 > In article <1995Jun7.201905.28513@cs.rochester.edu>,
 > Martin Jagersand <jag@cs.rochester.edu> wrote:
 > [snip]
 >I had hoped to find a lot of useful mechanical components in there.
 > [in the disk drive he took apart]

 BR> I have found that old printers have much more in the way of usefull
 BR> robot parts.  Many of the larger models have DC motors with optical
 BR> encoders.  You also get a toothed belt with matching pulleys that
 BR> are already mounted on your motor :) 

 BR> Brynn

I agree 100% here, Brynn..  I've found many dead Daisy-Wheel printers
over the years, and thankfully, most of the mechanical componants are
still in good shape.
 
  I'm still looking for some info on the pin-out of a couple of stepper-
motor driver IC's..  (a small 'toy'-grade robot I built ages ago, I want
to improve the mobility..  Tricycle-style, it uses two drive wheels, and
a swivel caster to steady the frame.  to make a turn, one motor shuts off
, while the other continues.  Only problem, one motor runs slightly faster
than the other, and it tends to lyst to the right. (Joke: Shades of Rush
Limbaugh, long before he became pompas...err.. Popular.) I've been
thinking of using two Mitsumi 4-phase (two 2-phase coil sets) steppers,
instead of the regular perminant magnet motors presently in use.
)  I got intrigued by the idea of using steppers, after a CP/M user's group
meeting, where one of the members showed a wall clock he had modified for
use as a stage prop, where he could control the speed & direction of
the clock from a remote computer.
 
  I heard someone else say, instead of a hard drive, that old Tandon
  TM-100-x drives, had enough parts for this.. (simple driving of a 2-phase
  (2 coil) stepper, using a step clock, a Logic-1 rotated the stepper one
  way, while a Logic-0 rotated it the other way.)
   
But, you're 100% right, though..  Printers are a better source of salvage
parts for robotics projects.  The present drive motors of my 'PoCo' came
from a pair of dead DECWriter-II's. (carriage)  Although I removed the
optical encoder. (Wasn't concerned on distance traveled, rather pure
movement.. a simple IR detector pair, and an old IR Motion sensor were
used for sensory of walls & people. (4 micro-switches on bumpers if it
still hit the wall.)
 
 Stephen
 stephen.griswold@circellar.com

___ Blue Wave/QWK v2.12
